<!doctype html>
<html lang="en">

<head>
  <title>Title</title>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

  <!-- Bootstrap CSS v5.2.1 -->
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.1/dist/css/bootstrap.min.css" rel="stylesheet"
    integrity="sha384-iYQeCzEYFbKjA/T2uDLTpkwGzCiq6soy8tYaI1GyVh/UjpbCx/TYkiZhlZB6+fzT" crossorigin="anonymous">

</head>

<body>
  <header>
    <!-- place navbar here -->
  </header>
  <main>
    <button type="button" class="btn btn-primary" data-bs-toggle="modal" data-bs-target="#myModal">
        打开模态框
    </button>

    <!-- 模态框 -->
    <div class="modal fade" id="myModal">
        <div class="modal-dialog modal-xl">
          <div class="modal-content">
            <div  class="modal-header">
              <h4 class="modal-title">模态框标题</h4>
              <button type="button" class="btn-close" data-bs-dismiss="modal"></button>
            </div>

            <!-- 模态框内容 -->
            <div class="modal-body">
              <img
                src="https://static.runoob.com/images/mix/img_fjords_wide.jpg"
                alt="img_fjords" decoding="async" class="d-block"
                style="width: 100%;">
                模态框内容
            </div>

            <!-- 模态框底部 -->
            <div class="modal-footer">
              <button type="button" class="btn  btn-primary" data-bs-dismiss="modal">关闭</button>
            </div>
          </div>
        </div>
    </div>
  </main>
  <footer>
    <!-- place footer here -->
  </footer>
  <!-- Bootstrap JavaScript Libraries -->
  <script src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.11.6/dist/umd/popper.min.js"
    integrity="sha384-oBqDVmMz9ATKxIep9tiCxS/Z9fNfEXiDAYTujMAeBAsjFuCZSmKbSSUnQlmh/jp3" crossorigin="anonymous">
  </script>

  <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.1/dist/js/bootstrap.min.js"
    integrity="sha384-7VPbUDkoPSGFnVtYi0QogXtr74QeVeeIs99Qfg5YCF+TidwNdjvaKZX19NZ/e6oz" crossorigin="anonymous">
  </script>
</body>

</html>